The movement that was popularized by the idea of individual liberty and separation of government power is: B. Enlightenment
The implementation of modern day democracy is the final goal of the enlightenment movement (at that time they were government by kings and nobles).
At that time, advocates of the enlightenment movement see that the government was too powerful since they can create any regulations they want without the approval of the people. So they fought for the separation of government power to limit government influence in people's life.